Field of the Invention
Embodiments of the present invention relates to display technical field, more particularly, relates to a thin film transistor and a method of manufacturing the thin film transistor, a display substrate and a display apparatus.
Description of the Related Art
Both an oxide thin film transistor (TFT) and an amorphous silicon TFT may be used as a driving tube in a display panel, such as, an organic light-emitting diode (OLED) panel, a polymer light-emitting diode (PLED) panel, etc. The oxide TFT has a current carrier concentration which is many times higher than that of the amorphous silicon TFT. In addition, since the oxide TFT may be manufactured by magnetron sputtering process, it does not need to substantially change the existing liquid crystal display panel production line. Also, since there is no restriction in the equipments for implementing ion implantation and laser crystallization, the oxide TFT is more favorable for the production of a large area display panel.
FIGS. 1(a)-1(c) show a flow chart of manufacturing an oxide TFT in the prior art. As shown in FIGS. 1(a)-1(c), for instance, the oxide TFT is configured to have a top gate configuration and use indium gallium zinc oxide (IGZO). Hereafter, it will describe a method of manufacturing the oxide TFT with an active layer made of the indium gallium zinc oxide in the prior art, the method comprises following steps of:
depositing a buffer layer 101 on a glass substrate; depositing an IGZO oxide semiconductor material layer on the buffer layer 101; forming an active layer pattern 102 by a patterning process; depositing a silicon oxide (SiOx) on the active layer pattern to form an etch barrier layer; etching the etch barrier layer to form an etch barrier layer pattern 103 as shown in Fig. (b), of course, the etch barrier layer pattern in the prior art may also comprise via holes corresponding to a source and a drain, respectively; and depositing a source and drain layer to form the source and the drain 104.
In the above method of manufacturing the thin film transistor in the prior art, the active layer is made of oxide semiconductor material. The oxide semiconductor material is very sensitive to a source and drain etching liquid. Thereby, in order to protect the active layer from the source and drain etching liquid during etching a metal layer to form the source and the drain, it is necessary to form an etch barrier layer on the active layer. Generally, it needs to perform a special patterning process on the etch barrier layer, which makes the production process of the oxide TFT complicated and results in a long production time and a high production cost.